package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${baseUrl}")  //@Value是一个基本数据类型的值的注入的注解
    String baseUrl;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //1. 解决重名问题
        //1.1 获取原始文件的名字，拿到扩展名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
//        System.out.println(suffix);
        //1.2 使用UUID生成一个新的字符串 与扩展名组合成一个新的文件名
        String newFileName = UUID.randomUUID()+suffix;
        System.out.println(newFileName);
//  2. 判断目录是否存在，不存在就创建
        File saveUrl = new File(baseUrl);
        if(!saveUrl.exists()){//如果指定目录不存在，就创建该目录
            saveUrl.mkdirs();
        }
        //3. 将file临时文件保存到指定位置baseUrl + newFilename

        try {
            file.transferTo(new File(baseUrl+newFileName));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(newFileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(baseUrl + name));

            //输出流，通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];//1024，1024.。。。。900
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
